The recent prolonged death of a convicted killer in Arizona — which that state's Republican senator, John McCain, described as tantamount to torture — led the state attorney general to call a halt to all executions, pending an investigation.

The incident should give Indiana, which recently announced it would use a new drug as part of its lethal injection protocol, plenty to think about. And Arizona to act upon.

Death row inmate Joseph Wood died nearly two hours after receiving a two-drug lethal injection combination. A properly administered lethal injection is supposed to last no more than 15 minutes.

The episode comes after botched executions in Oklahoma and Ohio. As drug-makers have begun refusing to sell their products for use in executions, states have scrambled to come up with new drug combinations.

Indiana's switch to Brevital is because of a shortage of sodium thiopental. Indiana officials say that the powerful anesthetic, which is used in hospitals, is appropriate for executions. It would be part of a three-drug protocol, which also includes pancuronium bromide and potassium chloride. Department of Correction spokesman Doug Garrison says the decision was made after consultations with pharmacists, other states and other experts.

The company that makes Brevital strongly disagrees, arguing that the drug has never been used in lethal injections and isn't approved for that purpose.

Indiana's first execution since 2009 — which could come later this year — may proceed exactly as expected. The drug newly added to the protocol could act just as Indiana officials appear confident it will.

But there's a chance that the state will find itself in the same situation that Arizona faced, struggling to explain a bungled execution that many would define as "cruel and unusual punishment."

That's not a chance that Indiana can afford to take. We're not arguing the merits of the death penalty. We'll leave that decades-long debate for later. But this much is clear: Gov. Mike Pence should order a moratorium on all executions until the state can be certain that its next execution won't resemble an experiment in state-sanctioned torture.